: The purchase of a new NMR spectrometer is proposed to bring new capabilities to the NMR facility in the Chemistry Department at the University of California, Irvine. The facility supports the research programs of a very active group of organic and bioorganic, many of whom have extensive support from the NIH for their health-related research. The current facility houses three old and heavily used NMR spectrometers. The greatest needs in the facility are for greater sensitivity to analyze small samples and for more instrument time to handle the heavy burden on the facility. A new 500MHz NMR spectrometer equipped with a 13 C/1H cryoprobe will be purchased through support from this proposal. The cryoprobe system is much more sensitive than a normal probe, which is itself more sensitive than our aging probes. We expect a better than four-fold improvement in sensitivity from the new instrument, and that added sensitivity will allow us to collect NMR data on much smaller samples, and to collect NMR data in much less time than is currently possible on limited quantities of material. The instrument will also take some of the burden off the existing machines and provide more instrument time. This new instrument will bring much needed new capabilities to the NMR facility and will greatly facilitate the research programs of the PI and co-PIs of this proposal.